**2. Insects as vectors of parasitic infections**

Most of the harmful parasitic infections are transmitted to humans by insects which have blood feeding behavior [7]. The parasitic infections such as malaria, lymphatic and non-lymphatic filariasis, leishmaniasis, sleeping sickness or the Human African Trypanosomiasis (HAT), and Chagas' disease or the American Trypanosomiasis, are a great burden to human health and life, especially in the poorest countries [8]. Malaria is a human parasitic disease with a very high burden. It is now especially important due to the widespread drug-resistant malaria and is at a risk of reemergence in many places worldwide. Malaria is transmitted by the bite of the mosquito species belonging to genus *Anopheles*, and filariasis is transmitted by the bite of *Culex* mosquito (**Table 1**). The parasitic zoonotic disease leishmaniasis is transmitted via the bite of phlebotomine sandflies in the Old and New World, tsetse fly is the vector of HAT, and triatomine kissing bugs are the vectors of Chagas' disease [8].

The vast expansion of these vector populations has become a growing concern and their control by different classes of insecticides is the most common method for their control, as insecticides suppress the insect populations by targeting insect metabolism in specific ways.


#### **Table 1.**

*Major group of insects causing human diseases and insecticides used for their control [7, 8].*
